This invention relates to a power drivable chuck, and particularly relates to a power drivable chuck having a shank-responsive locking element, and to an accessory having a shank configuration which facilitates assembly of the shank with the chuck.
Typically, chucks are designed with an opening for receiving a shank of an accessory, such as a bit, and locking the shank with the chuck. In a keyed chuck, the shank is inserted into an opening of a body of the chuck and a key is used to advance jaws within the body, in axial and radially inward directions to clamp about the inserted shank. In a keyless chuck, a mechanism is contained within the opening of the body, which is responsive to the insertion of the shank therein, for operating a locking mechanism also contained within the body.
In many instances, the locking mechanism includes a rolling element, such as a ball or a roll, which is moved aside from a biased locking position by the incoming shank, and returns to the locking position when an accommodating portion of the shank is aligned with the rolling element. While locking mechanisms with a rolling element perform very satisfactorily in many instances, there is a need for more firm locking mechanism for heavy duty tasks.
Also, there is a need for a shank-locking mechanism for chucks which is economical to manufacture, and easy to operate.
Further, there is a need for an accessory, such as a bit, formed with a shank which facilitates the operation of the shank-locking features of a chuck.
It is therefore, an object of this invention to provide a chuck having firm locking mechanism for heavy duty tasks.
It is also an object of this invention to provide a chuck having a shank-locking mechanism which is economical to manufacture, and easy to operate.
Further, it is an object of this invention to provide an accessory with a shank which facilitates the operation of shank-locking features of a chuck.
With these and other objects in mind, this invention contemplates a power drivable chuck for receiving and clamping a shank having at least one axial groove formed in the periphery thereof extending to a free end of the shank, and having a transaxial groove formed in a side wall, along an intermediate portion, of the axial groove. The chuck includes a body having an opening therein for receipt of the shank. The opening of the body is formed with a wall, and at least one axial rib formed on and extending inward from the wall of the opening of the body for receipt of the axial groove of the shank. A locking element is located within the opening of the body. Means, responsive to the insertion of the free end of the shank into the opening of the body, are provided for facilitating the directing of the locking element into the axial groove of the body to allow the shank to be moved further into the opening. Other means, responsive to an alignment of the locking element with the transaxial groove, are provided for directing the locking element into the transaxial groove to lock the shank with the chuck.
This invention further contemplates a power drivable chuck for receiving and clamping a shank having at least one axial groove formed in the periphery thereof extending to a free end of the shank, and having a transaxial groove formed in a side wall, along an intermediate portion, of the axial groove. The chuck includes a body having an axis and an axial opening formed therein for receipt of the shank. The opening of the body is formed with a wall, with at least one axial rib formed on and extending inward from the wall of the opening of the body for receipt of the axial groove of the shank. A slot is formed in the body and has a first end surface at first end thereof and a second end surface at a second end thereof spaced from the first end. A locking element is located within the opening of the body and has a portion thereof located within the slot for movement relative thereto within a plane between the first end surface and the second surface of the slot. A biasing element is provided for normally urging the locking element into engagement with the first end surface and allowing movement of the locking element toward the second end surface upon the application of a force sufficient to overcome an urging force as applied by the biasing element.
Additionally, this invention contemplates an accessory with a shank having an axis and a free end. An axial groove is formed in the shank through the free end thereof, and the axial groove is formed with a wall. A transaxial groove is formed in the wall of the axial groove at a location spaced inboard from the free end of the shank.
Other objects, features and advantages of the present invention will become more fully apparent from the following detailed description of the preferred embodiment, the appended claims and the accompanying drawings.